Fracture repair is the process of rejoining and realigning the ends of broken bones. Fracture repair is required when there is a need for restoration of the normal position and function of the broken bone. Throughout the stages of fracture healing, the bones must be held firmly in the correct position and supported until it is strong enough to bear weight. In the event the fracture is not properly repaired, malalignment of the bone may occur, resulting in possible physical dysfunction of the bone or joint of that region of the body.
Until the last century, physicians relied on casts and splints to support the bone from outside the body (external fixation). However, the development of sterile surgery reduced the risk of infection so that doctors could work directly with the bone and could implant materials in the body. Currently there are several internal approaches to repair, strengthen and support a fractured bone. They include the use of internal fixation devices, such as wires, plates, rods, pins, nails, and screws to support the bone directly, and the addition of bone cement mixtures, or bone void fillers to a fractured bone.
The addition of bone cements to a fractured bone for repairing bone and, for example, joining bones are well known in the art. Conventional bone cement injection devices have difficulty adjusting or controlling the injection volume or injection rate of the bone cement in real time in reaction to cancellous bone volume and density conditions encountered inside the fractured bone. Conventional bone cements also may cause complications that include the leakage of the bone cement to an area outside of the fractured bone site, which can result in soft tissue damage as well as nerve root pain and compression.
Thus, there is a need in the art for internal bone fixation devices that repair, strengthen and support a fractured bone using minimally invasive techniques, with ease of use, and minimal damage to the bone and supporting tissues.